When the hybrid engine is kobalt minen in parallel both engines can propel the car alone or together. A good example would be Toyotas' Hybrid Synergy Drive (HSD). Capable of being propelled at low speeds by the electric motor, the gas engine takes over at higher speeds. This allows both engines to perform in their optimal situation.
Deterioration is a function of temperature and charge level. Don't make the mistake of storing the battery fully charged, as that is the state where it breaks the fastest due to heat. Charge it to take it out and put it like that on the back seat of your car avoid direct sunlight and preferably put the mini lithium facts notebook on a firm flat surface while operating it.
This can be a problem for where the battery is not used that often but is can be important when it is needed for emergencies such as power outages. As the battery does not store well over extended amounts of time, it is possible that when they are needed they will not be usable. But for things that are used and recharged on a regular basis such as for portable electrical equipment, they are very good. But there is not always a slowing amount of capacity when they are getting old and it is possible for them to just not work without any reason being obvious.
The mating lithium bettery stock process between the two engines can be in series or in parallel. When the two powertrains are mated in series, only one of the motors controls the cars movement. The other one simply assists the first, dominant engine. This occurs most often in mild or assist hybrids. The Saturn Vue Green Line Belt Alternator System (BAS) is a good example. The concept vehicle named the Volt from GM is another good example of a series (but not a mild) hybrid.
Briefly relating back to overall size... many lithium 18650's will differ ever so slightly in length (measured in millimeters). This is mainly due to an added protection circuit. The circuit helps to prevent the battery from over-discharging, since Li-ion cells can easily become damaged if their power is drained below a particular voltage. The protection circuit also prevents the cell from being over-CHARGED as well. These cells are very sensitive. They must be handled carefully, gently, and as described above, must never run-down too far, or be charged over and above their threshold. They can actually explode if severely mistreated!
The Bosch AKE 30 Li is not only light, adaptable and maneuverable it also runs as quiet as a battery pack can make it. So you don't have to put up with headaches from the roaring gas engine or smoke fumes to make you sick to the stomach on a cold morning. The battery pack also has a turn-around rate of ninety minutes, and this is the amount of time it takes to charge it up fully. The Bosch AKE 30 Li has three 2.6 Ah lithium batteries and comes with a charger. It is a competitive product, definitely able to deliver as much or more than asked of it.